In semiconductor processing, many operations, such as ion implantation, may be performed on a workpiece or semiconductor wafer. As ion implantation processing technology advances, a variety of ion implantation temperatures at the workpiece can be implemented to achieve various implantation characteristics in the workpiece. For example, in conventional ion implantation processing, three temperature regimes are typically considered: cold implants, where process temperatures at the workpiece are maintained at temperatures below room temperature, hot or heated implants, where process temperatures at the workpiece are maintained at high temperatures typically ranging from 100−600° C., and so-called quasi-room temperature implants, where process temperatures at the workpiece are maintained at temperatures slightly elevated above room temperature, but lower than those used in high temperature implants, with quasi-room temperature implant temperatures typically ranging from 50−100° C.
Heated implants, for example, are becoming more common, whereby the process temperature is typically achieved via a heated chuck, where the workpiece is generally fixed to a clamping surface of the heated chuck during implantation by electrostatic force or mechanical clamping. For example, a heated electrostatic chuck (ESC) holds or clamps the workpiece using electrostatic force, while mechanical clamping mechanically maintains a position of the workpiece relative to the heated chuck by mechanical means. A conventional high temperature ESC, for example, comprises a set of heaters embedded under the clamping surface for heating the ESC and workpiece to the process temperature (e.g., 100° C.-600° C.), whereby a gas interface conventionally provides a thermal interface from the clamping surface to the backside of the workpiece.
During a heated implant, outgassing from the workpiece (e.g., from a substrate of the workpiece and/or films, photo resist, etc. formed on the substrate) tends to increase with processing temperature. Such outgassing can cause the pressure within the process chamber to increase, as well as introducing foreign, unwanted materials and gasses into the process chamber. An increase in pressure in the process chamber can cause negative effects on the ion beam and the process, thus lowering a throughput, as the implant is typically paused until the process chamber pressure (e.g., a vacuum) recovers to a stable condition.